scholarly journals 552 Comparison of Genetic Diversity in between Two Germplasm Banks Containing Lycopersicon esculentum Accessions

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 491A-491
Author(s):  
James Nienhuis ◽  
Julie Rodriguez ◽  
Wilber Phillips ◽  
Peter Hanson ◽  
Liliway Engle
Keyword(s):  
Genetic Diversity ◽  
Costa Rica ◽  
Lycopersicon Esculentum ◽  
Molecular Marker ◽  
Research And Development ◽  
Genetic Resources ◽  
Core Collection ◽  
Germplasm Bank ◽  
Development Center ◽  
Germplasm Banks

Worldwide, there are cuurently more than 60 germplasm banks that contain tomato (Lycopersicon esculentum) collections ranging is size from a few dozen to several thousands of accessions. In the utilization of these genetic resources sampling from only one germplasm bank may result in limiting available genetic diversity, whereas sampling from several germplasm banks may result in unnecessary redundancy. The current lack of knowledge regarding the relative magnitudes of genetic diversity contained within different collections makes it difficult to develop a core collection that maximizes genetic diversity. Two large tomato collections are housed at the Asian Vegetable Research and Development Center (AVRDC), Sanhua, Taiwan, R.O.C., and the Centro Agronomico Tropical de Investigacion y Enseoanza (CATIE), Turrialba, Costa Rica. Ninety-six accessions from CATIE and 102 accessions from AVRDC were randomly sampled from each base collection. The total of 198 accessions were charcterized for 103 polymorphic RAPD molecular marker bands. The results indicated that the two germplam banks sampled different genetic diversity. In addition, the magnitude of genetic diversity was greater in the AVRDC collection compared to CATIE.

scholarly journals RAPD Marker Facilitated Analysis of Genetic Diversity among Capsicum Genetic Resources from the Asian Vegetable Research and Development Center

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 544E-545
Author(s):  
Julie Villand ◽  
Terry Berke ◽  
Liwayway Engle ◽  
James Nienhuis
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Research And Development ◽  
Genetic Resources ◽  
Allelic Variation ◽  
Rapd Marker ◽  
Germplasm Collection ◽  
Pedigree Information ◽  
Marker Allele ◽  
Development Center

Significant effort has been made in the collection of Capsicum germplasm throughout the world for maintenance by genebanks. The largest Capsicum germplasm collection is held by the Asian Vegetable Research and Development Center (AVRDC), consisting of 6844 accessions and eight species. The paradox of any germplasm collection is that, as the number of accessions and the probability of preserving genetic variability increases, the ability of users to efficiently utilize this resource decreases. Genetic variation can be quantified using RAPD molecular marker allele frequency and allelic variation to understand the genetic structure and variation within and among populations. The comprehensive Capsicum collection held at the AVRDC provides an opportunity to sample a range of germplasm representative of the variability that exists in available Capsicum germplasm. Accessions were sampled from the AVRDC collection to represent the range of genetic variation available in Capsicum 1) based on cluster analysis using morphological traits among 1500 accessions and 2) based on pedigree information from the Capsicum breeding program. Our objectives include understanding the structure and magnitude of genetic diversity among these AVRDC accessions and comparing the genetic diversity within sub-populations of these accessions. RAPD fingerprints of these accessions were collected using markers dispersed over numerous linkage groups based on a genetic map we have constructed. RAPD band frequencies and RAPD band diversity were used to test differences among and within sub-populations. The understanding of the distribution of genetic variation among and within these sub-populations will be useful for prioritizing collection, conservation, and sampling of these genetic resources.

scholarly journals Genetic diversity in common bean accessions evaluated by means of morpho-agronomical and RAPD data

2007 ◽  
Vol 64 (3) ◽  
pp. 256-262 ◽  
Author(s):  
Alisson Fernando Chiorato ◽  
Sérgio Augusto Morais Carbonell ◽  
Luciana Lasry Benchimol ◽  
Marilia Barbosa Chiavegato ◽  
Luiz Antonio dos Santos Dias ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Common Bean ◽  
Genetic Similarity ◽  
Germplasm Conservation ◽  
Molecular Data ◽  
Ex Situ ◽  
Germplasm Bank ◽  
Improvement Programs ◽  
Improved Cultivars ◽  
Germplasm Banks

Germplasm banks store genotype samples, improved varieties, landraces and wild species, all generically denominated accessions. The importance of characterizing germplasm banks is based on the identification and knowledge of relevant traits for genetic improvement and ex situ germplasm conservation. Thus, the present study had as aim the evaluation of the genetic diversity among 220 accessions of a Brazilian common bean germplasm bank of the "Instituto Agronômico de Campinas" (IAC) by means of 23 morpho-agronomical descriptors and 19 RAPD loci. These accessions correspond to genotypes from the Andean and Middle American gene pool as well as from cultivars derived from common bean improvement programs. The Middle American accessions and the improved cultivars were clustered into one group, distinct from the one formed by the Andean accessions. In relation to the molecular data, 47% of the genetic similarity was detected among the Middle American accessions, and similar results were observed for the improved cultivars (50%). The Andean accessions revealed 60% of genetic similarity. The cluster constituted by the improved cultivars and the Middle American genotypes differed, basically, in tegument color. Both molecular and morpho-agronomical data sets were equally effective to quantify and organize the genetic diversity of common bean accessions. This information may be useful to direct crosses and for the proper organization of the IAC germplasm bank.

scholarly journals Comparison of Genetic Diversity between Nuña and and Other Andean bean (Phaseolus vulgaris) Populations

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 544C-544
Author(s):  
James Nienhuis ◽  
Paul Skroch ◽  
Steve Beebe
Keyword(s):  
Genetic Diversity ◽  
Energy Efficiency ◽  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Core Collection ◽  
Rapd Markers ◽  
Practical Consideration ◽  
Common Beans ◽  
Germplasm Bank ◽  
Wide Range

Nuñas are a type of common bean (Phaseolus vulgaris) that possess the unusual characteristic of popping or expanding their cotyledonary tissue when heated. Numerous landraces of nuña beans were domesticated in the Andean region of South America (Peru, Bolivia, and Ecuador) and have been grown and consumed in this region since antiquity. The practical consideration in the domestication of nuñas in the high Andes was likely due to the greater energy efficiency in cooking toasted vs. boiled seeds.The Phaseolus germplasm bank at CIAT (Centro Internacional de Agricultura Tropical) has developed a core collection of Andean beans that includes numerous nuña landraces. Based on the wide range of phaseolin types observed among nuña landraces, it has been hypothesized that nuñas may represent a greater source of genetic diversity compared to other landraces and cultivars of common bean. Eighty nuña accessions and 120 nonpopping common bean accessions were randomly sampled from the CIAT Andean germplasm core collection. The 200 accessions were characterized for 140 mapped RAPD markers. The objectives of our research were to 1) understand the genetic structure of nuña bean accessions relative to other Andean common beans, and 2) to measure the genetic distance and genetic diversity between nuña and other Andean bean populations.

Some recent issues on the conservation of crop genetic resources in developing countries

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 562-569 ◽  
Author(s):  
S Jana
Keyword(s):  
Genetic Diversity ◽  
Developing Countries ◽  
Plant Breeding ◽  
Genetic Resources ◽  
Core Collection ◽  
Ex Situ ◽  
Crop Genetic Resources ◽  
Core Collections ◽  
Global Food Security ◽  
Crop Genetic Diversity

Crop genetic resources (CGRs) are renewable resources. These resources are enriched rather than depleted by their use in research and plant breeding. Both at the time of Vavilov and, later, in the early 1970s, when concerted international efforts to collect and preserve CGRs started with the initiatives of the International Board for Plant Genetic Resources (IBPGR), CGRs were considered to be the common heritage of humankind. Now, they are widely accepted as "national heritage." Possible impacts of this nationalization on the utilization and enrichment of global crop genetic diversity and, consequently, on global food security are issues of great significance. At present, efficient management and adequate use of CGRs are more important concerns than their further exploration and collection. To increase the use of preserved CGRs in plant breeding, the formation of core collections, by selecting representative subsets from large ex situ collections of CGRs, was recommended in 1984. Since then, the core-collection strategy has been further justified as a practical approach to genetic resources management, as well as to their conservation. As a cost-saving germplasm-management strategy, the core-collection concept has considerable merit. However, the rapidly increasing popularity of core collections may undermine the genetic wealth stored in national gene banks of both developed and developing countries. Distinction is made between subsets of working collections and core collections. When a small number of CGRs is required for specific plant breeding purposes, a properly formed working collection is more useful than a representative collection. Despite the relative abundance of genetic diversity in crop plants in traditional agroecosystems, maintenance of these agroecosystems is not a realistic long-term alternative for preserving crop genetic diversity and ensuring global food security. What is needed in the "gene-rich" developing countries is the adoption of "biodiversity friendly" plant breeding and agricultural practices.Key words: crop genetic resources, core collection, germplasm conservation, in situ conservation, ex situ conservation, modern landraces.

scholarly journals Molecular characterization and genetic diversity of Jatropha curcas L. in Costa Rica

2016 ◽  
Author(s):  
Marcela Vásquez-Mayorga ◽  
Eric J Fuchs ◽  
Eduardo J Hernández ◽  
Franklin Herrera ◽  
Jesús Hernández ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Costa Rica ◽  
Jatropha Curcas ◽  
Geographical Origin ◽  
Wide Distribution ◽  
Costa Rican ◽  
Nrdna Its ◽  
Neighbor Joining ◽  
Germplasm Bank ◽  
Nj Tree

We estimated the genetic diversity of 50 Jatropha curcas Costa Rican samples using 18 EST-SSR, one G-SSR and nrDNA-ITS markers. We also evaluated the phylogenetic relationships among samples using nuclear ribosomal ITS markers. Non-toxicity was also evaluated using G-SSRs and SCARs markers. A Neighbor-Joining (NJ) tree and a Maximum Likelihood (ML) tree were constructed using SSR markers and ITS sequences, respectively. Heterozygosity was moderate (He = 0.346), but considerable when compared to worldwide values for J. curcas. The PIC (PIC = 0.276) and inbreeding coefficient (f = -0.102) were both low. Clustering was not related to the geographical origin of accessions but Costa Rican J. curcas consistently clustered as a separate group. International accessions clustered independently of collection sites suggesting a lack of genetic structure, probably due to a wide distribution of this crop and ample gene flow. Molecular markers identified only one non-toxic accession (JCCR-24) from Mexico. This work is part of a countrywide effort to characterize the genetic diversity of Jatropha curcas germplasm bank in Costa Rica.

Establishment of a cryopreserved gene bank of European elms

2004 ◽  
Vol 34 (1) ◽  
pp. 43-55 ◽  
Author(s):  
L Harvengt ◽  
A Meier-Dinkel ◽  
E Dumas ◽  
E Collin
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Liquid Nitrogen ◽  
Random Sample ◽  
Plant Material ◽  
Core Collection ◽  
Gene Bank ◽  
Ulmus Glabra ◽  
Negative Effect ◽  
Ulmus Laevis

Cryopreservation of a core collection of 444 elm (Ulmus spp.) clones in liquid nitrogen was carried out by two laboratories participating in a European project of conservation of elm genetic resources. Plant material, collected in nine European countries, represented a large sample of the genetic diversity within three European elm species and their hybrids. The cryopreservation technique used in both laboratories involved the stepwise freezing of cryotubes containing dormant buds. Comparisons with fresh buds showed that the cryopreservation treatment had no negative effect on the viability and regrowth potential of frozen buds. Tests on a random sample of 26 clones showed that direct regrowth of cryopreserved buds (i.e., through propagation by microcuttings) of Ulmus minor and Ulmus laevis was possible; conversely, Ulmus glabra could only be regrown through micrografting. Most thawed explants from all 26 clones survived through the whole cultivation phase and were successfully transferred to the field. A calculation of costs indicates that cryopreservation of elm buds is economically competitive to field clonal archives.

Genetic diversity and construction of core collection in Chinese wheat genetic resources

2008 ◽  
Vol 53 (10) ◽  
pp. 1518-1526 ◽  
Author(s):  
ChenYang Hao ◽  
YuChen Dong ◽  
LanFen Wang ◽  
GuangXia You ◽  
HongNa Zhang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Core Collection ◽  
Chinese Wheat

scholarly journals The impact of sample selection strategies on genetic diversity and representativeness in germplasm bank collections

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jorge Franco-Duran ◽  
José Crossa ◽  
Jiafa Chen ◽  
Sarah Jane Hearne
Keyword(s):  
Genetic Diversity ◽  
Crop Improvement ◽  
Sample Selection ◽  
Cost Effective ◽  
Fixed Number ◽  
Sample Sizes ◽  
Germplasm Bank ◽  
Selection Strategies ◽  
The Impact ◽  
Germplasm Banks

Abstract Background Germplasm banks maintain collections representing the most comprehensive catalogue of native genetic diversity available for crop improvement. Users of germplasm banks are interested in a fixed number of samples representing as broadly as possible the diversity present in the wider collection. A relevant question is whether it is necessary to develop completely independent germplasm samples or it is possible to select nested sets from a pre-defined core set panel not from the whole collection. We used data from 15,384, maize landraces stored in the CIMMYT germplasm bank to study the impact on 8 diversity criteria and the sample representativeness of: (1) two core selection strategies, a statistical sampling (DM), or a numerical maximization method (CH); (2) selecting samples of varying sizes; and (3) selecting samples of different sizes independently of each other or in a nested manner. Results Sample sizes greater than 10% of the whole population size retained more than 75% of the polymorphic markers for all selection strategies and types of sample; lower sample sizes showed more variability (instability) among repetitions; the strongest effect of sample size was observed on the CH-independent combination. Independent and nested samples showed similar performance for all the criteria for the DM method, but there were differences between them for the CH method. The DM method achieved better approximations to the known values in the population than the CH method; 2-d multidimensional scaling plots of the collection and samples highlighted tendency of sample selection towards the extremes of diversity in the CH method, compared with sampling more representative of the overall genotypic distribution of diversity under the DM method. Conclusions The use of core subsets of size greater than or equal to 10% of the whole collection satisfied well the requirement of representativeness and diversity. Nested samples showed similar diversity and representativeness characteristics as independent samples offering a cost effective method of sample definition for germplasm banks. For most criteria assessed the DM method achieved better approximations to the known values in the whole population than the CH method, that is, it generated more statistically representative samples from collections.

scholarly journals Common Vetch, Valuable Germplasm for Resilient Agriculture: Genetic Characterization and Spanish Core Collection Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Lucía De la Rosa ◽  
María Isabel López-Román ◽  
Juan M. González ◽  
Encarnación Zambrana ◽  
Teresa Marcos-Prado ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Core Collection ◽  
Animal Feed ◽  
Plant Genetic Resources ◽  
Wild Relatives ◽  
Agricultural System ◽  
Protein Profiles ◽  
Common Vetch ◽  
Breeding Programs

Common vetch (Vicia sativa L.) is a legume used for animal feed because of its high protein content and great capacity for nitrogen fixation, making this crop relevant in sustainable agriculture. The Spanish vetch collection, conserved at the Spanish Plant Genetic Resources Center (CRF), is one of the largest collections of this species worldwide, including landraces, wild relatives mainly collected in Spain, and commercial cultivars, but also accessions of international origin. The analysis of the genetic diversity of this material, whose genome has not been sequenced yet, and the assembly of a representative collection could play a pivotal role in conserving and exploiting these genetic resources in breeding programs mainly in those focused on consequences and demands of climate change. In this work, a set of 14 simple sequence repeat (SSR) reference alleles for genetic diversity analysis of the CRF vetch collection has been developed, used for genotyping more than 545 common vetch accessions from all over the world and validated. All the tested markers were polymorphic for the analyzed accessions. Overall, at least 86 different loci were identified with 2–11 alleles per locus with an average of 6.1 alleles per locus. Also, the analyses of the generated SSR database support that most of these SSR markers are transferable across closely related species of Vicia genus. Analysis of molecular variance revealed that wild relatives have a higher genetic diversity than landraces. However, cultivars have similar diversity than landraces, indicating that genetic variability has been barely lost due to the breeding of this legume. Low differences of genetic variations between Spanish and non-Spanish accessions have been observed, suggesting a high degree of diversity within Spanish genotypes, which provide 95% of the total genetic variation, so we have focused our efforts on characterizing genotypes of Spanish origin that were further studied using storage protein profiles. Based on SSR, seed protein profiles, and agromorphological and passport data, a vetch core collection (VCC) containing 47 V. sativa accessions of Spanish origin has been established. In this collection, the characterization has been expanded using ISSR markers, and it has been reevaluated with new agromorphological data, including drought tolerance characters. This VCC presents a minimum loss of genetic diversity concerning the total collection and constitutes an invaluable material that can be used in future breeding programs for direct use in a resilient agricultural system.

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